I try to make my own pcb :-) Details will follow but here the first facts:
- Main PCB will get µATX, ATX or E-ATX form factor
- Main PSR is default ATX PSR mounted in 19" server rack which the main pcb will be mounted
- BFL Chips will be solder on carrier PCB in one of actual CPU Socket form factor (e.g. LGA1155). They will get an copper heat spread on top mounted.
- Every Carrier can handle one to max 7 chips (maybe 8 depends on needed adress for PSRs)
- On Main PCB CPU sockets will be mounted to connect the BFL carrier and a proper CPU cooler solution
- Every BFL will get there own (maybe programmable) psr (which needs one own SPI address for psr controller) with sense lines as near as possible to the chips
- Option for external clock is planned (maybe need one more SPI address).
- BFL Chip Controller solution is selectable: AVR or Rasberry Pi (or other)
- Temperature will be measure by internal chip temp sensor
- KiCad will be used for planning the layout and design.
- The design files will be shared.
Ready:
- Documentation from BFL stored
- BFL Chips ordered and fully payed
- KiCad installed.
- BFL Chip symbol created for KiCad
Next Steps:
- Generate simple layout for carrier pcb
- Generate simple layout for main pcb
- Create chips to socket netlist
- Select psr module solution
Open questions:
- Documentation from BFL described Done signals in daisy chain mode. On SC Board instead chip done signals are directly connected to AVR. Why?
- What are the possible heat spread sizes for different LGA sockets? In fact also what are the dimensions of different cpu's?
- How much CPU sockets can be used on main pbc?
- Maybe because of large size 2 Layer board could be used for main pcb.
- Is the Rasberry Pi strong enough?
- When will I get my BFL chip order in hand? In 1st week of october as promised?
- How much are the costs of the more expensive parts?
My recent favorites:
- 8 BFL on LPGA-2011 Carrier with copper heat spread because of needed min. die size 42mm x 42 mm
- 8 PowerOne DP8120 POL controlled by DM7308 Power controller
- Rasberry Pi as Controlller with SPI Mode for controlling BFL Chips
- Fallback PSR DeltaOne D12S050201C with trim
References:
- BFL Chip description page https://forums.butterflylabs.com/announcements/3014-butterfly-labs-announces-bulk-chip-sales.html
- BFL Chip description link https://forums.butterflylabs.com/attachments/announcements/1321d1371338930-butterfly-labs-announces-bulk-chip-sales-bfl-sha2-spec-rev2.2-release.pdf
- Delta Electronics D12S050201C 20A DC/DC POL http://www.delta.com.tw/product/ps/dcdc/std/download/data_sheet/DS_D12S05020_10282008.pdf(Cheap and easy for one chip)
- PowerOne ZY1120 20A DC/DC POL http://www.power-one.com/sites/power-one.com/files/zy1120.pdf(Expensive still easy to use, parallel configuration possible)
- PowerOne DP8120 20A DC/DC POL Digital http://www.power-one.com/sites/power-one.com/files/documents/power/datasheet/dp8120_data_sheet_1r0.pdf(Programmable by DM7300G Power Controller)
- PowerOne DM7300G Power controller http://www.power-one.com/sites/power-one.com/files/documents/power/datasheet/dm7300_datasheet_rev_1r0.pdf(Power controller for PowerOne POL series)
To be continued.